Period: From May 2025      Issued on 14.05.2025 using data to the end of April 2025

Rainfall: 

Rainfall across much of Great Britain was very low in April, continuing the dry period that began in February. Many areas received less than half their normal rainfall, with parts of northern England and western Scotland recording below 30% of their April average. The exceptions to this pattern have been in Northern Ireland, where rainfall has been more normal, and in southern Wales, Cornwall and Devon, which experienced above-average April rainfall. The forecast (issued by the Met Office on 28.04.25) shows a signal for a hotter than average May-July, albeit with fairly balanced likelihoods of wet and dry conditions. The dry start to May is likely to be followed by a period of more unsettled weather, especially in western parts.

River flows:

River flows in April were very low in most areas, with exceptionally low flows in northern England and southern and eastern Scotland. The exceptions were in groundwater-dominated catchments, where flows were sustained by the above-normal stores resulting from wet conditions in winter, and the south-west, where flows were normal to above normal due to the recent rainfall. The outlook for May is for below normal to low flows in almost all areas, except the South West in which river flows are likely to be normal. For May-July, river flows are likely to continue to be below normal to low, although western Scotland is more likely to experience normal flows. The dry start to May increases the likelihood that low to exceptionally low flows in some areas persist into the summer.

Groundwater:

Groundwater levels in April have declined over the last month but remain normal across much of southern England. Below-normal levels have been recorded in the Cotswolds, Dorset and eastern Yorkshire, while above normal levels persist in the southern Chalk in Essex and Hertfordshire. The outlook for May indicates these patterns are likely to persist, with normal to above-normal levels in the South, especially the Chalk, and below normal levels in northern England. Very similar patterns are expected over the period May-July. Although the overall tendency is to return towards normal levels, low groundwater levels in some areas are likely to continue for several months.